Imaging Characteristics of Anomalous Left Coronary Artery From the Pulmonary Artery Meng-Luen Lee, M.D., Ing-Sh Chiu, Ph.D., Shyh-Jye Chen, Wun-Tsong Chaou Summary: The authors report the imaging characteristics of the anomalous origin of the left coronary artery from the pulmonary artery in a 6 1 /2-month-old male infant using electrocardiography, echocardiography, angiography, and electron-beam computed to- mography. The patient presented with tachycardia, prolonged and interrupted feeding, failure to thrive, and myocardial infarction, and after diagnosis of the anomalous origin of the left coronary artery, survived the reimplantation of the left coronary artery directly to the ascending aorta. When reviewed 7 months after surgery, echocardiog- raphy showed improved left ventricular function and surface electrocardiography showed regression of pathologic Q waves in leads I, V 4 ,V 5 , and V 6 . Key Words: Anomalous coronary artery—Echocardiography—Angiography— Electron-beam computed tomography—Myocardial infarction. Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) was first described in 1933 as a distinctive syndrome (1). The clinical manifestations of patients with the ALCAPA syndrome reflect a physi- ologic continuum and range from myocardial infarction and congestive heart failure in early “infantile type” to an asymptomatic cardiac murmur of mitral regurgitation and finally to syncope or sudden cardiac death in the late “adult type” (2). Before birth, there is equal systemic and pulmonary arterial pressure that secures anterograde flow of saturated blood in the anomalous left coronary artery. Because of physiologic pulmonary hypertension, there are usually no symptoms in the neonatal period associated with ALCAPA syndrome. With the normal regression of the muscular elements of the pulmonary vascular bed and subsequent fall in pulmonary artery pressure to normal levels in the first 6 to 8 weeks of life, the pressure in the pulmonary artery is not sufficient for myocardial perfusion. As a result, retrograde flow of blood develops from the anomalous left coronary artery to the pulmonary trunk via collateral channels of the right coronary artery. This leads to myocardial ischemia and infarction from a myocardial steal phenomenon if collateral myocardial flow is not adequate. For this rea- son, survival beyond infancy is uncommon because of chronic myocardial ischemia and intractable heart fail- ure; however, death is uncommon during the first 2 months of life (3). The ALCAPA syndrome, which is characterized by chronic myocardial hypoperfusion, is potentially reversible (4) if the patient undergoes surgical correction once the diagnosis is made. The present au- thors report on an infant with ALCAPA syndrome and emphasize the imaging characteristics that may permit the correct diagnosis. CASE REPORT A6 1 /2-month-old male infant was referred from a local pediatric clinic because of poor weight gain, a gallop rhythm, and a faint grade II/VI systolic ejection murmur. On the first day of admission, his body weight was 6.5 kg (5 percentile), body length 64 cm (5 percentile), blood pressure 81/58 mm Hg (mean, 66 mm Hg), heart rate 169/min, and respiratory rate 29/min. Cardiac examina- tion was notable for a third heart sound gallop rhythm, a From the Department of Pediatrics, the Division of Pediatric Cardi- ology, and the Pediatric Intensive Care Unit (M.-L.L.); the Division of Pediatric Neurology and Head (W.-T.C.); Changhua Christian Hospi- tal, Changhua, Taiwan; the Department of Surgery (I.-S.C.), the Divi- sion of Cardiovascular Surgery; and the Department of Medical Imag- ing (S.-J.C.), College of Medicine, National Taiwan University Hos- pital, Taipei, Taiwan. Address correspondence to Dr Meng-Luen Lee, Department of Pe- diatrics, Changhua Christian Hospital, No. 135 Nanhsiao St., Changhua 50050, Taiwan. Journal of Thoracic Imaging 17:96–100 © 2002 Lippincott Williams & Wilkins, Inc., Philadelphia 96